Opto-electronic semiconductor sensors used in scanning video systems, of the area as well as line scanning type, use charges which, in dependence on the respective brightness applied to the sensor provides for charge transfer in synchronism with clock signals applied to one or more outputs, to be then sensed as a sensing signal respresentative of the brightness of the image on the particular spot. The course of the signal within a cycling period is such that a maximum value, dependent on brightness, is always followed by a minimum value, which is independent of brightness of the particular spot which has been illuminated.
Many types of semiconductor sensors have two outputs, the output signals of which are 180.degree. out-of-phase with respect to each other. Since the output signals from the sensors are very low, amplifiers are used which, in some types of these sensors, are already integrated with the sensor itself.
Amplifiers coupled to the sensors, particularly in view of the low output from the sensors themselves, introduce a noise signal which is additive to the actual utilization or sensed signal. This noise signal interferes with proper sensing of the sensed signal.